This invention relates to a process for improving regenerated catalysts which are suitable for reuse in the hydroprocessing of naphthas and gas oils.
Hydrocarbon fuels are now being required to be produced with extremely low sulfur content, for example less than 0.05 wt % sulfur in diesel fuel, and 500 ppm sulfur or less in gasoline. To meet these requirements refineries have to hydroprocess naphthas and gas oils at higher temperatures and under more severe conditions. In order to maintain throughput and profitability, higher activity catalysts are required for these operations. These catalysts are frequently regenerated for reuse after being employed. However, they may suffer a significant loss in activity after undergoing regeneration, as compared to a fresh catalyst.
Thus, an object of the present invention is to provide an effective, inexpensive method of enhancing the activity of regenerated catalysts.